Structure
type | ACADEMIC status | COMPLETED year | 2019
The Superstructure
The equipment required for this program is often as heavy as a vehicle. And there are multiple sets of such equipment required in a particular lab module. The lab module itself features a rather heavy ballast slab to help stem the vibrations and oscillations caused by lateral forces on the building. To this end, the superstructure is also built up by layering various technologies with each other. All joints between the layers of the structure have an isolating or damping mechanism that help curtail undesired movement, while ensuring adequate strength. The superstructure also props up the solar surface at an angle of 19 degrees to the south, ideal for capturing solar energy at this latitude.
Below is an exploded axonometric illustration of the many sub-structures that make up the superstructure.
The main frame of the superstructure is a single bay portal frame constructed using a pair of built-up I-Sections, braced with riveted steel strips and welded gusset plates joining the pair of I-sections. The vertical portion of this frame is anchored into the ground through a precast RCC pile. The horizontal portion of the frame is pitched at an angle to hold up the Solar roof.
The lab slabs are supported by a system of vierendeel girders and castellated girders. The vierendeel girder is a built-up steel girder that is 2.3M deep, spanning the dimension of the portal frame and distributing the load from the lab slab to the four stanchions of the portal frames. In addition to load distribution, it also serves as a lateral bracing member that keeps the portal frame bending and breaking under torsional stress. The slab rests directly on the castellated girders, which in turn transfers its load to the vierendeel girder.
The lab module walling system (isolated from the lab slab) is supported by a 3.5M deep truss with vibration dampers. This truss rests directly on the vierendeel girder, transferring the load onto the horizontal members so the that lab slab is not overloaded.
All structural systems are castellated or vierendeel trusses so as to increase the effective depth while conserving the amount of materials used.
The roof, or solar surface on which the solar panels are placed is made up of a series of I-sections spanning the portal bay, purlins, and corrugated sheets that create a plane for the solar panels to rest on, and act as a shield against the hot southwestern sun.
Using Waste-less Materials
Choosing "sustainable" materials for a project such as this is rather difficult, as some functions will require to be encased in concrete boxes or will require a heavy-duty slab - which increases the construction carbon footprint by large amounts. In some cases, using alternative building materials is simply not possible.
However, using structural materials such as steel allows the possibility of dismantling and recycling or reusing, whereas if reinforced concrete frames were used for the larger structures, this would generate a massive amount of waste and rubble during destruction of the building.
Furthermore, this kind of a programme may be obsolete in the next fifty years; and the next scientific programme may be obsolete thirty years after that, and so on and so forth. Unlike residential spaces or commercial spaces, the programme calls for highly specific architecture liable to change within a couple of decades. Considering the time-scales we want to design urban spaces for, rather than continue the cycle of quick-construction and subsequent rubble creation, we use materials that create minimal rubble.
The concrete elements that are necessary (such as the lab slab and the slab for the equipment bays) are precast and shipped to site, reducing the chance of construction-related chemicals affecting the ecosystem on the site. Below is an infographic showing the materials used and the advantages of using these materials in the reduction of wasteful development.
Post-Structural Ecosystem
Building a sprawling laboratory complex along the ecotone at the edge of a heavily forested grove is generally and unsustainable practice. But, given the site conditions, and the necessity of building such structures, how would one ensure the ecosystem is conserved to the fullest extent?
At the outset, an ecosystem like this may be conserved by identifying and protecting the keystone species of trees and plants so that cutting and transplanting does not affect these plants. If the keystone species are removed, the entire ecosystem could collapse. I developed a way to collate and design with the trees on site with the mapping I conducted.
Secondly, when choosing materials, especially concrete and cement based materials and mortars, ensure that they are precast, preferably off site or inside of an in-situ closed structure, as the particulates from these construction processes are highly detrimental for plants (particles enter and block the stomata of the leaves, making it impossible for a plant to photosynthesise, and soluble chemicals enter the water cycle that affects the pH of the soil, killing important microorganisms and microfauna in the rhizosphere.
And lastly, in the process of design, ensure that the building is designed to be dismantled without creating excessive waste on site. Excavations of vast areas for basements affect soil stratification, upending or destroying micro-ecologies that may have taken thousands if not millions of years to form. With current technology, the average time period of an RCC building is about 75-100 years. At our current capacity, we are liable to not only destroy the existing ecosystems, but through repeated cycles of development, destroy the earth's ability to host any ecosystem in the future.
For this nanotechnology centre, the design reduced the footprint of the building to only the structural stanchions and the circulation core (as well as the ground floor labs, which basically go against all the canon's stated above). In addition to this, the ground plane was layered with organic matter as shown in the illustration below.
The roof and external walls of the building are designed to channel water downwards into bio-swales spanning the portal bay (as seen in the plan below). The bio-swales overflow into beds of moss and mulch, which serve two purposes: they absorb and store excess water and prevent the topsoil layer from being eroded. The excess water store in the moss leaches gradually into the soil and ensures that the soil is kept hydrated through all seasons. As is shown in the infographic above, the edges of the built area are blanketed in moss. Under the suspended labs of the building, pockets of leaf litter and other decaying organic matter are present which encourage the buildup of nutrient rich soil even in the absence of a full ecosystem.
The building, as mentioned before, straddles the ecotone between a dense grove (in the north) and a nearly barren scrubland (to the south). Part of the design strategy when it comes to landscape is to plant keystone species of trees to the south of the building, creating an "interrupted ecosystem" which can be modulated to allow functionality of the building during usage, and once the building is dismantled (in about 200 or so years), the ecosystem begins to bridge this "interruption" with the understory (weeds and shrub growth that are encouraged by the landscape strategy) creating the first succession into the moss-and-leaf-litter laden soil during the monsoon.
The keystone trees planted to the south of the building as part of the landscape strategy ensure that birds, insects and pollinators fly across or pass through this interrupted ecotone, spreading seeds and spores and other genetic information with them, speeding up the process of ecosystem regeneration.
This is the last page of the expanded series about my design dissertation completed in April 2019. On the links below, you can see what I'm working on in "Current Projects", or view a competition entry that follows the canons of a closed loop system known as "The Green Loo Deal".
Updated: 19 August, 2020